Five times stronger by weight than steel, Kevlar – the para-aramid synthetic fiber of exceptional strength and stiffness better known (to chemists at least) as poly-paraphenylene terephthalamide – has saved countless lives from countless bullets. It was invented by Stephanie Louise Kwolek, a research chemist at DuPont for forty years, in 1965 AD. She invented other things of course (she was inducted into the National Inventors Hall of Fame in 1995) and won many prestigious awards, but she will forever be linked to bullet-resistant vests.

Born to Polish immigrants in New Kensington, Pennsylvania in 1923, Stephanie inherited her love of discovery from her naturalist father John and her love of fabric from her seamstress mother Nellie. At one point in her youth, she wanted to become a fashion designer, but her mother warned her she would probably starve in that profession, so Stephanie became a chemist. When she graduated from the women’s college of Carnegie-Mellon University, she applied for a position as a research chemist with the DuPont Company. The intelligent Kwolek was offered a position and joined the company’s facility in Buffalo in 1946.

Kwolek was immediately engaged in several projects, primarily the search for new polymers using a condensation process that could take place at lower temperatures than before. In doing so, she unexpectedly discovered that under certain conditions, molecules of rod-like polyamides would form liquid crystalline solutions. These solutions could be spun into fibers of extreme tensile strength, and were resistant to corrosion and flames … Kevlar. Kwolek kept inventing more synthetic materials; she held 17 U.S. patents when she died in 2014, much honored and quite well-off financially (better than most fashion designers, anyway).